Estimated Compression Loss Due to Hinged Hand Holes

Tim asks:

We are trying calculate the estimated loss of compression strength in some boxes that we are running for a customer when we had hinged hand holes. The boxes are approximately 17”x15”x13 ½” and run out of 42MW-26-42-26-42 BC. Is there an accurate formula or rule of thumb about compression loss for this?

When under compression, the weakest portions of a box side panel are the diagonals connecting the opposing corners. If the hand holes are located outside of these concentrated stress fault lines, then their effect on the compression strength is minimized or at least greatly reduced.

In George Maltenfort’s book, Performance and Evaluation of Shipping Containers, he suggests compression losses should be in the range of 10-20%. Of course, board quality and grade, design specifications, etc. can influence this number.

In his book, George also recommends that you request a letter of indemnification since the holes may suffer abuse and damage when the boxes are placed in use. If the containerboard becomes bent, torn or damaged at the hand hole, the compression strength and box integrity can be significantly reduced.

– Ralph

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